Alright thanks all for your help, so is good to use the "Bind to file" every time i use tables in the project and/or file path with variable.
The part that got me confused is that it works even if i don't bind to file.
I use inputs and insert c:\folder\table.xlsx, this is adding it to variable1.
This variable1 is the file path to "c:\folder\table.xlsx".
I use get line action from the table with settings >>>load from file+save changes of table to file, where the file path is variable1 take columns and add them to variables.
All this works without any problems even in multithread.